1. Field of the Invention
The present invention generally relates to a connector and more particularly to a connector disposed on an end of a cable for use when connected to a board side connector mounted on an end of a printed board of an electronic device.
2. Description of the Related Art
In signal transmission between computer devices, a balanced transmission method has been employed in which two signal lines, namely, a first signal line and a second signal line are assigned to a single signal, a positive signal is transmitted via the first signal line, and a negative signal opposite to the positive signal is transmitted via the second signal line so as to perform transmission with high reliability in a trend toward high-speed signal transmission. Various types of connectors supporting this method have been commercialized as products.
A cable side connector has connectors at both ends of a cable. One connector is connected to a board side connector of one computer device and the other connector is connected to a board side connector of the other computer device for use, so that the two computer devices are connected.
FIG. 1 is a schematic diagram showing a conventional cable side connector 10 and a board side connector 40. The cable side connector 10 is disposed on an end of a cable 11 and is connected to the board side connector 40 for use, which is mounted on an end of a printed board 41 of an electronic device.
The cable side connector 10 includes a connector module 12 disposed inside a shield cover assembly 30, in which an end of an electrical wire inside the cable 11 is soldered with the connector module 12.
As shown in FIG. 2, the connector module 12 includes a printed board assembly 20 installed inside a contact assembly 13.
As shown in FIG. 3, the contact assembly 13 includes a pair of signal contacts 15-1 and 15-2 and a platy ground contact 16 pressed into an insulator block 14 from a backside thereof. In the insulator block 14, on a protrusion unit 14a protruding forward in a plate-like manner, the signal contacts 15-1 and 15-2 and the ground contact 16 are arranged. This portion constitutes a connector connection portion 18 and the connector connection portion 18 is inserted into the board side connector 40. Terminal portions 15-1a, 15-2a, and 16a are arranged in a protruding manner on the backside of the insulator block 14.
The printed board assembly 20 relays communication between the contact assembly 13 and the cable 11. The printed board assembly 20 includes a printed board 21 on which a capacitor element 25 and a resistance element 26 are mounted. The printed board 21 includes a signal pattern 22 and a ground pattern 23 formed on a top face and a bottom face thereof. Plural lines arranged in parallel constitute the signal pattern 22 and a remaining area constitutes the ground pattern 23. The capacitor element 25 and the resistance element 26 are connected in parallel with each signal pattern 22 and constitute an equalizer circuit unit 27.
In the printed board assembly 20, a front side end of the printed board 21 is fitted into a groove portion 14b of the insulator block 14, an end of the signal pattern 22 is soldered with the terminal portions 15-1a and 15-2a, and an end of the ground pattern 23 is soldered with the terminal portion 16a. 
The electrical wire at the end of the cable 11 is soldered with an opposite end of the printed board 21.
The above-mentioned equalizer circuit unit 27 has a function of correcting distortion of wave forms of signals transmitted through the cable 11. Presence of the equalizer circuit unit 27 improves reliability of signal transmission. In addition, it is possible to increase a length of the cable 11 to about two times a conventional length of about 5 m, namely, 10 m.
Patent Document 1: Japanese Laid-Open Patent Application No. 2003-059593
However, the above-mentioned cable side connector 10 requires the printed board assembly 20 and the signal contacts 15-1 and 15-2 as independent parts, so that the number of parts is large.